1. Field of the Invention
The present invention relates to a wire bonding apparatus, and more particularly, to a wire bonding apparatus with an improved bonding head.
2. Description of Related Art
Generally, a wire-bonding process for bonding a chip to a lead frame with a plurality of formed leads, and then connecting the chip to leads with wire (generally, gold wire) of very small diameter, is realized by a bonding head which is the core portion of a wire bonding apparatus.
There are several kinds of bonding heads for such wire bonding apparatus depending on the driving method. A bonding head (name of model is UTC-100) manufactured by Shinkawa of Japan uses an X, Y table to which a ball screw and a linear motor guide are attached for transferring a transducer in the X and Y directions, and a motor and a cam for transferring it in the Z direction.
And, in another example of a bonding head, an X, Y table is used for transferring a transducer in the X and Y directions, and a linear motor is used for transferring it in the Z direction.
A wire bonding apparatus using a conventional bonding head, as described above, has the following problems.
First, the ball screw or the linear motor used for transferring the transducer in the X, Y and Z directions, causes energy loss by friction and abrasion of components, and thereby requires a periodic replacement of the components.
Second, the structure of the bonding head is very complicated, and thereby requires many assembling operation processes making it difficult to improve productivity.
Third, in order to achieve high speed wire bonding, an AC or DC servo motor and a driving apparatus need to be attached to the X, Y table which raises production costs due to increased equipment cost.
Fourth, the X, Y table is heavy and therefore requires a large installation space.